UST896047I4

ABSTRACT

ISOPRENE IS POLYMERIZED BY A HYDROCARBON LITHIUM CATALYST IN THE PRESENCE OF 15 TO 300 PARTS PER MILLION OF ALPHA-ACETYLENE OR LITHIUM ACETYLIDE OR AN ALLENE OF 3 TO 8 CARBON ATOMS AS A MODIFIER, THE AMOUNT OF CATALYST BEING IN SUBSTANTIAL EXCESS OF THE STOICHIOMETRIC AMOUNT REQUIRED TO REACT WITH THE MODIFIER, SUCH EXCESS BEING SUFFICIENT TO INITIATE POLYMERIZATION.



